Staple cartridge comprising a releasable adjunct material

ABSTRACT

A surgical stapling apparatus is disclosed which comprises cartridge body and a layer. The layer is implantable against tissue by staples deployed from the cartridge body and deformed by an anvil. The cartridge and the layer comprise co-operating features which reduce relative movement between the cartridge and the layer. Such co-operating features can also releasably retain the layer to the cartridge body. In addition to or in lieu of the above, the anvil and the layer comprise co-operating features which reduce relative movement between the anvil and the layer. Such co-operating features can also releasably retain the layer to the anvil. In certain instances, the layer can be positioned against the anvil, but releasably attached to the cartridge. The layer can comprise buttress material and/or a tissue thickness compensator, for example.

BACKGROUND

The present invention relates to stapling instruments and, in various embodiments, to a surgical stapling instrument for producing one or more rows of staples.

A stapling instrument can include a pair of cooperating elongate jaw members, wherein each jaw member can be adapted to be inserted into a patient and positioned relative to tissue that is to be stapled and/or incised. In various embodiments, one of the jaw members can support a staple cartridge with at least two laterally spaced rows of staples contained therein, and the other jaw member can support an anvil with staple-forming pockets aligned with the rows of staples in the staple cartridge. Generally, the stapling instrument can further include a pusher bar and a knife blade which are slidable relative to the jaw members to sequentially eject the staples from the staple cartridge via camming surfaces on the pusher bar and/or camming surfaces on a wedge sled that is pushed by the pusher bar. In at least one embodiment, the camming surfaces can be configured to activate a plurality of staple drivers carried by the cartridge and associated with the staples in order to push the staples against the anvil and form laterally spaced rows of deformed staples in the tissue gripped between the jaw members. In at least one embodiment, the knife blade can trail the camming surfaces and cut the tissue along a line between the staple rows. Examples of such stapling instruments are disclosed in U.S. Pat. No. 7,794,475, entitled SURGICAL STAPLES HAVING COMPRESSIBLE OR CRUSHABLE MEMBERS FOR SECURING TISSUE THEREIN AND STAPLING INSTRUMENTS FOR DEPLOYING THE SAME, the entire disclosure of which is hereby incorporated by reference herein.

The foregoing discussion is intended only to illustrate various aspects of the related art in the field of the invention at the time, and should not be taken as a disavowal of claim scope.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of the embodiments described herein are set forth with particularity in the appended claims. The various embodiments, however, both as to organization and methods of operation, together with advantages thereof, may be understood in accordance with the following description taken in conjunction with the accompanying drawings as follows:

FIG. 1 is a perspective view of a staple cartridge in accordance with at least one embodiment comprising a cartridge body and a layer releasably attached to the cartridge body by retractable retaining members;

FIG. 2 is a partial cross-sectional view of the staple cartridge of FIG. 1 illustrating the retaining members in an extended position;

FIG. 3 is a partial cross-sectional view of the staple cartridge of FIG. 1 illustrating the retaining members in a retracted position;

FIG. 4 is a partial perspective view of a staple cartridge in accordance with at least one embodiment comprising a cartridge body and a layer releasably attached to the cartridge body by a liftable retaining member;

FIG. 5 is a partial cross-sectional view of the staple cartridge of FIG. 4 illustrating the retaining member in a gripping position;

FIG. 6 is a partial cross-sectional view of the staple cartridge of FIG. 4 illustrating the retaining member in a lifted position;

FIG. 7 is a partial perspective view of an end effector assembly including a staple cartridge comprising a cartridge body and a cartridge layer releasably attached to the cartridge body and, in addition, an anvil layer releasably attached to the cartridge body;

FIG. 8 is a cross-sectional elevational view of the end effector assembly of FIG. 7;

FIG. 9 is a partial cross-sectional plan view of the end effector assembly of FIG. 7 illustrating the proximal ends of the cartridge layer and the anvil layer releasably attached to the cartridge body; and

FIG. 10 is a partial cross-sectional plan view of the end effector assembly of FIG. 7 illustrating the proximal ends of the cartridge layer and the anvil layer released from the cartridge body.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate various embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

The Applicant of the present application also owns the U.S. Patent Applications identified below which are each herein incorporated by reference in their respective entirety:

U.S. patent application Ser. No. 12/894,311, entitled SURGICAL INSTRUMENTS WITH RECONFIGURABLE SHAFT SEGMENTS; now U.S. Pat. No. 8,763,877;

U.S. patent application Ser. No. 12/894,340, entitled SURGICAL STAPLE CARTRIDGES SUPPORTING NON-LINEARLY ARRANGED STAPLES AND SURGICAL STAPLING INSTRUMENTS WITH COMMON STAPLE-FORMING POCKETS; now U.S. Pat. No. 8,899,463;

U.S. patent application Ser. No. 12/894,327, entitled JAW CLOSURE ARRANGEMENTS FOR SURGICAL INSTRUMENTS; now U.S. Pat. No. 8,978,956;

U.S. patent application Ser. No. 12/894,351, entitled SURGICAL CUTTING AND FASTENING INSTRUMENTS WITH SEPARATE AND DISTINCT FASTENER DEPLOYMENT AND TISSUE CUTTING SYSTEMS; now U.S. Pat. No. 9,113,864;

U.S. patent application Ser. No. 12/894,338, entitled IMPLANTABLE FASTENER CARTRIDGE HAVING A NON-UNIFORM ARRANGEMENT; now U.S. Pat. No. 8,864,007;

U.S. patent application Ser. No. 12/894,369, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING A SUPPORT RETAINER; now U.S. Patent Application Publication No. 2012/0080344;

U.S. patent application Ser. No. 12/894,312, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING MULTIPLE LAYERS; now U.S. Pat. No. 8,925,782;

U.S. patent application Ser. No. 12/894,377, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE; now U.S. Pat. No. 8,393,514;

U.S. patent application Ser. No. 12/894,339, entitled SURGICAL STAPLING INSTRUMENT WITH COMPACT ARTICULATION CONTROL ARRANGEMENT; now U.S. Pat. No. 8,840,003;

U.S. patent application Ser. No. 12/894,360, entitled SURGICAL STAPLING INSTRUMENT WITH A VARIABLE STAPLE FORMING SYSTEM; now U.S. Pat. No. 9,113,862;

U.S. patent application Ser. No. 12/894,322, entitled SURGICAL STAPLING INSTRUMENT WITH INTERCHANGEABLE STAPLE CARTRIDGE ARRANGEMENTS; now U.S. Pat. No. 8,740,034;

U.S. patent application Ser. No. 12/894,350, entitled SURGICAL STAPLE CARTRIDGES WITH DETACHABLE SUPPORT STRUCTURES; now U.S. Patent Application Publication No. 2012/0080478;

U.S. patent application Ser. No. 12/894,383, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING BIOABSORBABLE LAYERS; now U.S. Pat. No. 8,752,699;

U.S. patent application Ser. No. 12/894,389, entitled COMPRESSIBLE FASTENER CARTRIDGE; now U.S. Pat. No. 8,740,037;

U.S. patent application Ser. No. 12/894,345, entitled FASTENERS SUPPORTED BY A FASTENER CARTRIDGE SUPPORT; now U.S. Pat. No. 8,783,542;

U.S. patent application Ser. No. 12/894,306, entitled COLLAPSIBLE FASTENER CARTRIDGE; now U.S. Pat. No. 9,044,227;

U.S. patent application Ser. No. 12/894,318, entitled FASTENER SYSTEM COMPRISING A PLURALITY OF CONNECTED RETENTION MATRIX ELEMENTS; now U.S. Pat. No. 8,814,024;

U.S. patent application Ser. No. 12/894,330, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX AND AN ALIGNMENT MATRIX; now U.S. Pat. No. 8,757,465;

U.S. patent application Ser. No. 12/894,361, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX; now U.S. Pat. No. 8,529,600;

U.S. patent application Ser. No. 12/894,367, entitled FASTENING INSTRUMENT FOR DEPLOYING A FASTENER SYSTEM COMPRISING A RETENTION MATRIX; now U.S. Pat. No. 9,033,203;

U.S. patent application Ser. No. 12/894,388, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX AND A COVER; now U.S. Pat. No. 8,474,677;

U.S. patent application Ser. No. 12/894,376, entitled FASTENER SYSTEM COMPRISING A PLURALITY OF FASTENER CARTRIDGES; now U.S. Pat. No. 9,044,228;

U.S. patent application Ser. No. 13/097,865, entitled SURGICAL STAPLER ANVIL COMPRISING A PLURALITY OF FORMING POCKETS; now U.S. Pat. No. 9,295,464;

U.S. patent application Ser. No. 13/097,936, entitled TISSUE THICKNESS COMPENSATOR FOR A SURGICAL STAPLER; now U.S. Pat. No. 8,657,176;

U.S. patent application Ser. No. 13/097,954, entitled STAPLE CARTRIDGE COMPRISING A VARIABLE THICKNESS COMPRESSIBLE PORTION; now U.S. Patent Application Publication No. 2012/0080340;

U.S. patent application Ser. No. 13/097,856, entitled STAPLE CARTRIDGE COMPRISING STAPLES POSITIONED WITHIN A COMPRESSIBLE PORTION THEREOF; now U.S. Patent Application Publication No. 2012/0080336;

U.S. patent application Ser. No. 13/097,928, entitled TISSUE THICKNESS COMPENSATOR COMPRISING DETACHABLE PORTIONS; now U.S. Pat. No. 8,746,535;

U.S. patent application Ser. No. 13/097,891, entitled TISSUE THICKNESS COMPENSATOR FOR A SURGICAL STAPLER COMPRISING AN ADJUSTABLE ANVIL; now U.S. Pat. No. 8,864,009;

U.S. patent application Ser. No. 13/097,948, entitled STAPLE CARTRIDGE COMPRISING AN ADJUSTABLE DISTAL PORTION; now U.S. Pat. No. 8,978,954;

U.S. patent application Ser. No. 13/097,907, entitled COMPRESSIBLE STAPLE CARTRIDGE ASSEMBLY; now U.S. Pat. No. 9,301,755;

U.S. patent application Ser. No. 13/097,861, entitled TISSUE THICKNESS COMPENSATOR COMPRISING PORTIONS HAVING DIFFERENT PROPERTIES; now U.S. Pat. No. 9,113,865;

U.S. patent application Ser. No. 13/097,869, entitled STAPLE CARTRIDGE LOADING ASSEMBLY; now U.S. Pat. No. 8,857,694;

U.S. patent application Ser. No. 13/097,917, entitled COMPRESSIBLE STAPLE CARTRIDGE COMPRISING ALIGNMENT MEMBERS; now U.S. Pat. No. 8,777,004;

U.S. patent application Ser. No. 13/097,873, entitled STAPLE CARTRIDGE COMPRISING A RELEASABLE PORTION; now U.S. Pat. No. 8,740,038;

U.S. patent application Ser. No. 13/097,938, entitled STAPLE CARTRIDGE COMPRISING COMPRESSIBLE DISTORTION RESISTANT COMPONENTS; now U.S. Pat. No. 9,016,542;

U.S. patent application Ser. No. 13/097,924, entitled STAPLE CARTRIDGE COMPRISING A TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,168,038;

U.S. patent application Ser. No. 13/242,029, entitled SURGICAL STAPLER WITH FLOATING ANVIL; now U.S. Pat. No. 8,893,949;

U.S. patent application Ser. No. 13/242,066, entitled CURVED END EFFECTOR FOR A STAPLING INSTRUMENT; now U.S. Patent Application Publication No. 2012/0080498;

U.S. patent application Ser. No. 13/242,086, entitled STAPLE CARTRIDGE INCLUDING COLLAPSIBLE DECK; now U.S. Pat. No. 9,055,941;

U.S. patent application Ser. No. 13/241,912, entitled STAPLE CARTRIDGE INCLUDING COLLAPSIBLE DECK ARRANGEMENT; now U.S. Pat. No. 9,050,084;

U.S. patent application Ser. No. 13/241,922, entitled SURGICAL STAPLER WITH STATIONARY STAPLE DRIVERS; now U.S. Pat. No. 9,216,019;

U.S. patent application Ser. No. 13/241,637, entitled SURGICAL INSTRUMENT WITH TRIGGER ASSEMBLY FOR GENERATING MULTIPLE ACTUATION MOTIONS; now U.S. Pat. No. 8,789,741;

U.S. patent application Ser. No. 13/241,629, entitled SURGICAL INSTRUMENT WITH SELECTIVELY ARTICULATABLE END EFFECTOR; now U.S. Patent Application Publication No. 2012/0074200;

U.S. application Ser. No. 13/433,096, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF CAPSULES; now U.S. Pat. No. 9,301,752;

U.S. application Ser. No. 13/433,103, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF LAYERS; now U.S. Pat. No. 9,433,419;

U.S. application Ser. No. 13/433,098, entitled EXPANDABLE TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,301,753;

U.S. application Ser. No. 13/433,102, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A RESERVOIR; now U.S. Pat. No. 9,232,941;

U.S. application Ser. No. 13/433,114, entitled RETAINER ASSEMBLY INCLUDING A TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,386,988;

U.S. application Ser. No. 13/433,136, entitled TISSUE THICKNESS COMPENSATOR COMPRISING AT LEAST ONE MEDICAMENT; now U.S. Patent Application Publication No. 2012/0241492;

U.S. application Ser. No. 13/433,141, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CONTROLLED RELEASE AND EXPANSION; now U.S. Patent Application Publication No. 2012/0241493;

U.S. application Ser. No. 13/433,144, entitled TISSUE THICKNESS COMPENSATOR COMPRISING FIBERS TO PRODUCE A RESILIENT LOAD; now U.S. Pat. No. 9,277,919;

U.S. application Ser. No. 13/433,148, entitled TISSUE THICKNESS COMPENSATOR COMPRISING STRUCTURE TO PRODUCE A RESILIENT LOAD; now U.S. Pat. No. 9,220,500;

U.S. application Ser. No. 13/433,155, entitled TISSUE THICKNESS COMPENSATOR COMPRISING RESILIENT MEMBERS; now U.S. Pat. No. 9,480,476;

U.S. application Ser. No. 13/433,163, entitled METHODS FOR FORMING TISSUE THICKNESS COMPENSATOR ARRANGEMENTS FOR SURGICAL STAPLERS; now U.S. Patent Application Publication No. 2012/0248169;

U.S. application Ser No. 13/433,167, entitled TISSUE THICKNESS COMPENSATORS; now U.S. Pat. No. 9,220,501;

U.S. application Ser. No. 13/433,175, entitled LAYERED TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,332,974;

U.S. application Ser. No. 13/433,179, entitled TISSUE THICKNESS COMPENSATORS FOR CIRCULAR SURGICAL STAPLERS; now U.S. Pat. No. 9,364,233;

U.S. application Ser. No. 13/763,028, entitled ADHESIVE FILM LAMINATE; now U.S. Pat. No. 9,282,962;

U.S. application Ser. No. 13/433,115, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CAPSULES DEFINING A LOW PRESSURE ENVIRONMENT; now U.S. Pat. No. 9,204,880;

U.S. application Ser. No. 13/433,118, entitled TISSUE THICKNESS COMPENSATOR COMPRISED OF A PLURALITY OF MATERIALS; now U.S. Pat. No. 9,414,838;

U.S. application Ser. No. 13/433,135, entitled MOVABLE MEMBER FOR USE WITH A TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,517,063;

U.S. application Ser. No. 13/433,140, entitled TISSUE THICKNESS COMPENSATOR AND METHOD FOR MAKING THE SAME; now U.S. Pat. No. 9,241,714;

U.S. application Ser. No. 13/433,129, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF MEDICAMENTS; now U.S. Pat. No. 9,211,120;

U.S. application Ser. No. 11/216,562, entitled STAPLE CARTRIDGES FOR FORMING STAPLES HAVING DIFFERING FORMED STAPLE HEIGHTS, now U.S. Pat. No. 7,669,746;

U.S. application Ser. No. 11/714,049, entitled SURGICAL STAPLING DEVICE WITH ANVIL HAVING STAPLE FORMING POCKETS OF VARYING DEPTHS, now U.S. Patent Application Publication No. 2007/0194082;

U.S. application Ser. No. 11/711,979, entitled SURGICAL STAPLING DEVICES THAT PRODUCE FORMED STAPLES HAVING DIFFERENT LENGTHS, now U.S. Pat. No. 8,317,070;

U.S. application Ser. No. 11/711,975, entitled SURGICAL STAPLING DEVICE WITH STAPLE DRIVERS OF DIFFERENT HEIGHT, now U.S. Patent Application Publication No. 2007/0194079;

U.S. application Ser. No. 11/711,977, entitled SURGICAL STAPLING DEVICE WITH STAPLE DRIVER THAT SUPPORTS MULTIPLE WIRE DIAMETER STAPLES, now U.S. Pat. No. 7,673,781;

U.S. application Ser. No. 11/712,315, entitled SURGICAL STAPLING DEVICE WITH MULTIPLE STACKED ACTUATOR WEDGE CAMS FOR DRIVING STAPLE DRIVERS, now U.S. Pat. No. 7,500,979;

U.S. application Ser. No. 12/038,939, entitled STAPLE CARTRIDGES FOR FORMING STAPLES HAVING DIFFERING FORMED STAPLE HEIGHTS, now U.S. Pat. No. 7,934,630;

U.S. application Ser. No. 13/020,263, entitled SURGICAL STAPLING SYSTEMS THAT PRODUCE FORMED STAPLES HAVING DIFFERENT LENGTHS, now U.S. Pat. No. 8,636,187;

U.S. application Ser. No. 13/118,278, entitled ROBOTICALLY-CONTROLLED SURGICAL STAPLING DEVICES THAT PRODUCE FORMED STAPLES HAVING DIFFERENT LENGTHS, now U.S. Pat. No. 9,237,891;

U.S. application Ser. No. 13/369,629, entitled ROBOTICALLY-CONTROLLED CABLE-BASED SURGICAL END EFFECTORS, now U.S. Pat. No. 8,800,838;

U.S. application Ser. No. 12/695,359, entitled SURGICAL STAPLING DEVICES FOR FORMING STAPLES WITH DIFFERENT FORMED HEIGHTS, now U.S. Pat. No. 8,464,923;

U.S. application Ser. No. 13/072,923, entitled STAPLE CARTRIDGES FOR FORMING STAPLES HAVING DIFFERING FORMED STAPLE HEIGHTS, now U.S. Pat. No. 8,567,656;

U.S. application Ser. No. 13/766,325, entitled LAYER OF MATERIAL FOR A SURGICAL END EFFECTOR; now U.S. Patent Application Publication No. 2013/0256380;

U.S. application Ser. No. 13/763,078, entitled ANVIL LAYER ATTACHED TO A PROXIMAL END OF AN END EFFECTOR; now U.S. Patent Application Publication No. 2013/0256383;

U.S. application Ser. No. 13/763,094, entitled LAYER COMPRISING DEPLOYABLE ATTACHMENT MEMBERS; now U.S. Patent Application Publication No. 2013/0256377;

U.S. application Ser. No. 13/763,106, entitled END EFFECTOR COMPRISING A DISTAL TISSUE ABUTMENT MEMBER; now U.S. Pat. No. 9,592,050;

U.S. application Ser. No. 13/433,147, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CHANNELS; now U.S. Pat. No. 9,351,730;

U.S. application Ser. No. 13/763,112, entitled SURGICAL STAPLING CARTRIDGE WITH LAYER RETENTION FEATURES; now U.S. Patent Application Publication No. 2013/0256379;

U.S. application Ser. No. 13/763,035, entitled ACTUATOR FOR RELEASING A TISSUE THICKNESS COMPENSATOR FROM A FASTENER CARTRIDGE; now U.S. Patent Application Publication No. 2013/0214030;

U.S. application Ser. No. 13/763,042, entitled RELEASABLE TISSUE THICKNESS COMPENSATOR AND FASTENER CARTRIDGE HAVING THE SAME; now U.S. Patent Application Publication No. 2013/0221063;

U.S. application Ser. No. 13/763,048, entitled FASTENER CARTRIDGE COMPRISING A RELEASABLE TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,700,317;

U.S. application Ser. No. 13/763,054, entitled FASTENER CARTRIDGE COMPRISING A CUTTING MEMBER FOR RELEASING A TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,272,406;

U.S. application Ser. No. 13/763,065, entitled FASTENER CARTRIDGE COMPRISING A RELEASABLY ATTACHED TISSUE THICKNESS COMPENSATOR; now U.S. Pat. No. 9,566,061;

U.S. application Ser. No. 13/763,021, entitled STAPLE CARTRIDGE COMPRISING A RELEASABLE COVER; now U.S. Pat. No. 9,386,984;

U.S. application Ser. No. 13/763,078, entitled ANVIL LAYER ATTACHED TO A PROXIMAL END OF AN END EFFECTOR; now U.S. Patent Application Publication No. 2013/0256383;

U.S. application Ser. No. 13/763,095, entitled LAYER ARRANGEMENTS FOR SURGICAL STAPLE CARTRIDGES; now U.S. Pat. No. 9,770,245;

U.S. application Ser. No. 13/763,147, entitled IMPLANTABLE ARRANGEMENTS FOR SURGICAL STAPLE CARTRIDGES; now U.S. Patent Application Publication No. 2013/0153636;

U.S. application Ser. No. 13/763,192, entitled MULTIPLE THICKNESS IMPLANTABLE LAYERS FOR SURGICAL STAPLING DEVICES; now U.S. Pat. No. 9,615,826;

U.S. application Ser. No. 13/763,161, entitled RELEASABLE LAYER OF MATERIAL AND SURGICAL END EFFECTOR HAVING THE SAME; now U.S. Patent Application Publication No. 2013/0153641;

U.S. application Ser. No. 13/763,177, entitled ACTUATOR FOR RELEASING A LAYER OF MATERIAL FROM A SURGICAL END EFFECTOR; now U.S. Pat. No. 9,585,657;

U.S. application Ser. No. 13/763,037, entitled STAPLE CARTRIDGE COMPRISING A COMPRESSIBLE PORTION; now U.S. Patent Application Publication No. 2014/0224857;

U.S. application Ser. No. 13/433,126, entitled TISSUE THICKNESS COMPENSATOR COMPRISING TISSUE INGROWTH FEATURES; now U.S. Pat. No. 9,320,523;

U.S. application Ser. No. 13/433,132, entitled DEVICES AND METHODS FOR ATTACHING TISSUE THICKNESS COMPENSATING MATERIALS TO SURGICAL STAPLING INSTRUMENTS; now U.S. Patent Application Publication No. 2013/0256373.

U.S. application Ser. No. 13/851,703, entitled FASTENER CARTRIDGE COMPRISING A TISSUE THICKNESS COMPENSATOR INCLUDING OPENINGS THEREIN; now U.S. Pat. No. 9,572,577;

U.S. application Ser. No. 13/851,676, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A CUTTING MEMBER PATH; now U.S. Patent Application Publication No. 2014/0291379;

U.S. application Ser. No. 13/851,693, entitled FASTENER CARTRIDGE ASSEMBLIES; now U.S. Pat. No. 9,332,984;

U.S. application Ser. No. 13/851,684, entitled FASTENER CARTRIDGE COMPRISING A TISSUE THICKNESS COMPENSATOR AND A GAP SETTING ELEMENT; now U.S. Patent Application Publication No. 2014/0291380;

U.S. patent application Ser. No. 14/187,383, entitled IMPLANTABLE LAYERS AND METHODS FOR ALTERING IMPLANTABLE LAYERS FOR USE WITH SURGICAL FASTENING INSTRUMENTS, now U.S. Patent Application Publication No. 2015/0238185;

U.S. patent application Ser. No. 14/187,386, entitled IMPLANTABLE LAYERS AND METHODS FOR ALTERING ONE OR MORE PROPERTIES OF IMPLANTABLE LAYERS FOR USE WITH FASTENING INSTRUMENTS, now U.S. Patent Application Publication No. 2015/0239180;

U.S. patent application Ser. No. 14/187,390, entitled IMPLANTABLE LAYERS AND METHODS FOR MODIFYING THE SHAPE OF THE IMPLANTABLE LAYERS FOR USE WITH A SURGICAL FASTENING INSTRUMENT, now U.S. Patent Application Publication No. 2015/0238188;

U.S. patent application Ser. No. 14/187,389, entitled IMPLANTABLE LAYER ASSEMBLIES, now U.S. Pat. No. 9,757,124;

U.S. patent application Ser. No. 14/187,385, entitled IMPLANTABLE LAYERS COMPRISING A PRESSED REGION, now U.S. Pat. No. 9,693,777;

U.S. patent application Ser. No. 14/187,384, entitled FASTENING SYSTEM COMPRISING A FIRING MEMBER LOCKOUT, now U.S. Pat. No. 9,775,608; and

U.S. patent application Ser. No. 14/516,277, entitled STAPLE CARTRIDGE COMPRISING AN ADJUNCT MATERIAL, now U.S. Patent Application Publication No. 2016/0106426.

Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. It will be understood by those skilled in the art, however, that the embodiments may be practiced without such specific details. In other instances, well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described in the specification. Those of ordinary skill in the art will understand that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and illustrative. Variations and changes thereto may be made without departing from the scope of the claims.

The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a surgical system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” referring to the portion closest to the clinician and the term “distal” referring to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute.

Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the person of ordinary skill in the art will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, those of ordinary skill in the art will further appreciate that the various instruments disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the instruments can be inserted directly into a patient's body or can be inserted through an access device that has a working channel through which the end effector and elongated shaft of a surgical instrument can be advanced.

Many of the above-listed patent applications disclose various layers which are used in connection with a staple cartridge. When staples are deployed from the staple cartridge, the staples can capture at least one layer and implant the layer, or layers, against the tissue. Provided below is a brief description of a surgical stapling system. The staple cartridges and the layers disclosed herein can be used with this surgical stapling system and/or any suitable stapling system.

A surgical stapling system can comprise a shaft and an end effector extending from the shaft. The end effector comprises a first jaw and a second jaw. The first jaw comprises a staple cartridge. The staple cartridge is insertable into and removable from the first jaw; however, other embodiments are envisioned in which a staple cartridge is not removable from, or at least readily replaceable from, the first jaw. The second jaw comprises an anvil configured to deform staples ejected from the staple cartridge. The second jaw is pivotable relative to the first jaw about a closure axis; however, other embodiments are envisioned in which first jaw is pivotable relative to the second jaw. The surgical stapling system further comprises an articulation joint configured to permit the end effector to be rotated, or articulated, relative to the shaft. The end effector is rotatable about an articulation axis extending through the articulation joint. Other embodiments are envisioned which do not include an articulation joint.

The staple cartridge comprises a cartridge body. The cartridge body includes a proximal end, a distal end, and a deck extending between the proximal end and the distal end. In use, the staple cartridge is positioned on a first side of the tissue to be stapled and the anvil is positioned on a second side of the tissue. The anvil is moved toward the staple cartridge to compress and clamp the tissue against the deck. Thereafter, staples removably stored in the cartridge body can be deployed into the tissue. The cartridge body includes staple cavities defined therein wherein staples are removably stored in the staple cavities. The staple cavities are arranged in six longitudinal rows. Three rows of staple cavities are positioned on a first side of a longitudinal slot and three rows of staple cavities are positioned on a second side of the longitudinal slot. Other arrangements of staple cavities and staples may be possible.

The staples are supported by staple drivers in the cartridge body. The drivers are movable between a first, or unfired position, and a second, or fired, position to eject the staples from the staple cavities. The drivers are retained in the cartridge body by a retainer which extends around the bottom of the cartridge body and includes resilient members configured to grip the cartridge body and hold the retainer to the cartridge body. The drivers are movable between their unfired positions and their fired positions by a sled. The sled is movable between a proximal position adjacent the proximal end and a distal position adjacent the distal end. The sled comprises a plurality of ramped surfaces configured to slide under the drivers and lift the drivers, and the staples supported thereon, toward the anvil.

Further to the above, the sled is moved distally by a firing member. The firing member is configured to contact the sled and push the sled toward the distal end. The longitudinal slot defined in the cartridge body is configured to receive the firing member. The anvil also includes a slot configured to receive the firing member. The firing member further comprises a first cam which engages the first jaw and a second cam which engages the second jaw. As the firing member is advanced distally, the first cam and the second cam can control the distance, or tissue gap, between the deck of the staple cartridge and the anvil. The firing member also comprises a knife configured to incise the tissue captured intermediate the staple cartridge and the anvil. It is desirable for the knife to be positioned at least partially proximal to the ramped surfaces such that the staples are ejected ahead of the knife.

An end effector assembly 1000 is depicted in FIGS. 1-3. The end effector assembly 1000 comprises a first jaw 1001 and a second jaw 1002. The first jaw 1001 comprises a staple cartridge 1005. The staple cartridge 1005 is readily removable from the first jaw 1001 and can be replaced with another staple cartridge. Other embodiments are envisioned in which the staple cartridge 1005 is not readily removable from the first jaw 1001. The staple cartridge 1005 comprises a cartridge body 1010 and an implantable layer 1020. The cartridge body 1010 comprises a proximal end 1011, a distal end 1012, and a deck 1013 configured to support tissue. As discussed in greater detail further below, the layer 1020 is releasably retained to the deck 1013. The cartridge body 1010 further comprises a longitudinal slot 1014 and a plurality of staple cavities 1015 defined in the deck 1013. The staple cartridge 1005 further comprises staples 1040, and/or any other suitable fastener, removably stored in the staple cavities 1015 and staple drivers 1050 configured to lift the staples 1040 toward the deck 1013. The drivers 1050, and the staples 1040 supported thereon, are movable between an unfired position (FIG. 2) and a fired position (FIG. 3) by a firing member, such as sled 1060, for example. The sled 1060 can be pushed forward by a firing bar 1061 (FIG. 8) or, alternatively, the sled 1060 can be integrally formed with a firing bar. In either event, the sled 1060 comprises ramped surfaces 1063 (FIG. 3) configured to slide under the staple drivers 1050 and lift the staple drivers 1050 upwardly as the sled 1060 is advanced from a proximal position (FIGS. 8 and 9) toward a distal position (FIG. 3).

The second jaw 1002 comprises an anvil 1030 configured to deform the staples 1040. The second jaw 1002 is rotatable relative to the first jaw 1001 and, thus, the anvil 1030 is rotatable relative to the staple cartridge 1005; however, certain embodiments are envisioned in which the staple cartridge 1005 is rotatable relative to the anvil 1030. The sled 1060 and/or the firing bar 1061 can include a first cam 1067 (FIG. 8) configured to engage the first jaw 1001 and a second cam 1069 (FIG. 8) configured to engage the second jaw 1002 as the sled 1060 and the firing bar 1061 are advanced distally. The first cam 1067 and the second cam 1069 can co-operate to position the anvil 1030 relative to the staple cartridge 1005 and define a tissue gap therebetween. The first jaw 1001 comprises a first cam slot 1007 defined therein configured to receive the first cam 1067 and the second jaw 1002 comprises a second cam slot 1009 defined therein configured to receive the second cam 1069. The sled 1060 and/or the firing bar 1061 can comprise a cutting surface, such as a knife edge 1062 (FIG. 8), for example, configured to incise the tissue and the layer 1020 captured between the anvil 1030 and the staple cartridge 1005.

Referring again to FIGS. 1-3, the layer 1020 is releasably retained to the cartridge body 1010. The layer 1020 comprises a proximal end 1021 positioned over the proximal end 1011 of the cartridge body 1010 and a distal end 1022 positioned over the distal end 1012. The staple cartridge 1005 further comprises a layer retainer 1070 which is movable between a first position in which the layer retainer 1070 releasably holds the distal end 1022 of the layer 1020 to the distal end 1012 of the cartridge body 1010 (FIG. 2) and a second position in which the distal end 1022 of the layer 1020 is released from the distal end 1012 (FIG. 3). The staple cartridge 1005 actually comprises two layer retainers 1070—a first layer retainer 1070 positioned on a first side of the longitudinal slot 1014 and a second layer retainer 1070 positioned on a second side of the longitudinal slot 1014; however, a staple cartridge can comprise any suitable number of layer retainers. The first layer retainer 1070 is aligned with a first row of staple cavities 1015 and/or staple drivers 1050 in the cartridge body 1010 and the second retainer 1070 is aligned with a second row of staple cavities 1015 and/or staple drivers 1050. Each layer retainer 1070 comprises at least one pin 1073 which is received within a pin aperture 1023 defined in the layer 1020 when the layer retainer 1070 is in its first position (FIG. 2). In various instances, the pin 1073 and the pin aperture 1023 can be sized and configured such that there is an interference fit therebetween which can hold the distal end 1022 of the layer 1020 to the distal end 1012 of the cartridge body 1010. When the layer retainer 1070 is moved into its second position (FIG. 3), the pin 1073 is removed, or at least substantially removed, from the pin aperture 1023 and, as a result, the layer 1020, or at least the distal end 1022 of the layer 1020, may no longer be connected to the cartridge body 1010, as discussed in greater detail further below.

Each layer retainer 1070 is movable from its first position—in which it is engaged with the layer 1020—to its second position—in which it is disengaged from the layer 1020—by a staple driver 1050. The staple drivers 1050 are arranged in a proximal-to-distal manner between the proximal end 1011 and the distal end 1012 of the cartridge body 1010 wherein the distal-most staple drivers, i.e., staple drivers 1050 d, defeat the layer retainers 1070 when the staple drivers 1050 d are lifted toward the deck 1013 by the sled 1060. Each distal staple driver 1050 d comprises an actuator 1051 extending distally therefrom which is configured to contact a switch arm 1071 extending proximally from the layer retainer 1070 when the staple driver 1050 d is moved between its unfired position (FIG. 2) and its fired position (FIG. 3). The switch arm 1071 extends from a fulcrum 1078 of the layer retainer 1070 wherein the fulcrum 1078 is positioned, or positionable, against a pivot surface 1018 defined in the cartridge body 1010 and is configured to permit the layer retainer 1070 to rotate between its first position (FIG. 2) and its second position (FIG. 3) when the switch arm 1071 is driven upwardly by the staple driver 1050 d. Although the layer retainer 1070 may rotate between its first position and its second position, the pin 1073 of the layer retainer 1070 can be constrained such that it translates along a longitudinal path. In at least one instance, the cartridge body 1010 further comprises a pin slot 1074 configured to closely receive the pin 1073 which can limit the movement of the pin 1073 to motion along a vertical axis, for example. The distal driver 1050 d can rotate the switch arm 1071 upwardly until the switch arm 1071 abuts the pivot surface 1078. At such point, the distal driver 1050 d is at its fully-fired position.

As discussed above, the layer retainer 1070 is movable between a first position in which it holds the layer 1020 to the cartridge body 1010 and a second position in which the layer 1020 is released from the cartridge body 1010. When the layer retainer 1070 is in its first position, the pin 1073 extends above the deck 1013 of the cartridge body 1010. When the layer retainer 1070 is moved into its second position, the pin 1073 is lowered relative to the deck 1013 and is positioned flush with or below the deck 1013. In such circumstances, the pin 1073 can be completely removed from the pin aperture 1023 defined in the layer 1020. Other embodiments are envisioned in which the pin 1073 extends above the deck 1013 when the layer retainer 1070 is in its second position. In such a position, the pin 1073 may or may not be partially positioned within the pin aperture 1023 defined in the layer 1020. In the event that the pin 1073 is still partially positioned within the pin aperture 1020 when the layer retainer 1070 is in its second position, the layer 1020 may still slip off of the pins 1073 and allow the layer 1020 to be detached from the cartridge body 1010. In various instances, a clearance fit may exist between the pins 1073 and the layer apertures 1023.

The staple cartridge 1005 can include a biasing member, such as a spring, for example, configured to bias the layer retainers 1070 into their first positions. In some instances, the staple cartridge 1005 can comprise a first biasing member which biases the first layer retainer 1070 into its first portion and a second biasing member which biases the second layer retainer 1070 into its first position. When the distal drivers 1050 d push the layer retainers 1070 into their second positions, the distal drivers 1050 d can overcome the biasing forces applied by the biasing members.

The layer retainers 1070 hold the layer 1020 to the cartridge body 1010 before the sled 1060 and the firing bar 1061 are advanced distally during a firing stroke. This arrangement can be helpful to hold the layer 1020 in position while the staple cartridge 1005 is positioned relative to the tissue that is to be stapled. Once the staple cartridge 1005 has been suitably positioned relative to the tissue, the anvil 1030 can be moved into a closed position to clamp the tissue against the layer 1020. At such point, the sled 1060 and the firing bar 1061 can be advanced distally through their firing stroke. The layer retainer 1070 can hold the layer 1020 to the cartridge body 1010 during the entirety of the firing stroke or, alternatively, during a portion of the firing stroke. In various instances, the layer retainer 1070 may not be release the layer 1020 from the cartridge body 1010 until or after all of the staples 1040 have been fully fired. In some instances, the layer retainer 1070 can release the layer 1020 prior to, or immediately prior to, the completion of the firing stroke In any event, the layer retainer 1070 can prevent or inhibit the layer 1020 from being pushed distally by the knife edge 1062 when the knife edge 1062 is moved distally to transect the layer 1020. In the event that the sled 1060 and the firing bar 1061 are not advanced through their full firing stroke, the layer retainers 1070 may not be defeated by the distal drivers 1050 d and, as such, the layer retainers 1070 may continue to hold the layer 1020 to the cartridge body 1010. The pins 1073 of the layer retainers 1070 and the pin apertures 1023 of the layer 1020 can be sized and configured to provide a certain amount of retention force therebetween which can resist the movement of the layer 1020 prior to and during the firing stroke but permit the layer 1020 to be pulled away from the cartridge body 1010 in the event that the firing stroke is not completed.

Turning now to FIGS. 4-6, an end effector assembly 1100 comprises a first jaw 1001 and a second jaw 1002. The first jaw 1001 comprises a staple cartridge 1105. The staple cartridge 1105 is readily removable from the first jaw 1001 and can be replaced with another staple cartridge. Other embodiments are envisioned in which the staple cartridge 1105 is not readily removable from the first jaw 1001. The staple cartridge 1105 comprises a cartridge body 1110 and an implantable layer 1120. The cartridge body 1110 comprises a proximal end 1111 (FIGS. 9 and 10), a distal end 1112, and a deck 1113 configured to support tissue. As discussed in greater detail further below, the layer 1120 is releasably retained to the deck 1113. The cartridge body 1110 further comprises a longitudinal slot 1114 and a plurality of staple cavities 1015 defined in the deck 1113. The staple cartridge 1105 further comprises staples 1040, and/or any other suitable fastener, removably stored in the staple cavities 1015 and staple drivers 1150 configured to lift the staples 1040 toward the deck 1113. The drivers 1150, and the staples 1040 supported thereon, are movable between an unfired position (FIG. 8) and a fired position (FIGS. 5 and 6) by a firing member, such as sled 1060, for example. The sled 1060 can be pushed forward by a firing bar 1061 (FIG. 8) or, alternatively, the sled 1060 can be integrally formed with a firing bar. In either event, the sled 1060 comprises ramped surfaces 1063 (FIGS. 5 and 6) configured to slide under the staple drivers 1150 and lift the staple drivers 1150 upwardly as the sled 1060 is advanced from a proximal position (FIGS. 8 and 9) toward a distal position (FIG. 3).

The second jaw 1002 comprises an anvil 1030 configured to deform the staples 1040. The second jaw 1002 is rotatable relative to the first jaw 1001 and, thus, the anvil 1030 is rotatable relative to the staple cartridge 1105; however, certain embodiments are envisioned in which the staple cartridge 1105 is rotatable relative to the anvil 1030. The sled 1060 and/or the firing bar 1061 can include a first cam 1067 (FIG. 8) configured to engage the first jaw 1001 and a second cam 1069 (FIG. 8) configured to engage the second jaw 1002 as the sled 1060 and the firing bar 1061 are advanced distally. The first cam 1067 and the second cam 1069 can co-operate to position the anvil 1030 relative to the staple cartridge 1105 and define a tissue gap therebetween. The first jaw 1001 comprises a first cam slot 1007 (FIGS. 2 and 3) defined therein configured to receive the first cam 1067 and the second jaw 1002 comprises a second cam slot 1009 (FIGS. 2 and 3) defined therein configured to receive the second cam 1069. The sled 1060 and/or the firing bar 1061 can comprise a cutting surface, such as a knife edge 1062 (FIG. 8), for example, configured to incise the tissue and the layer 1120 captured between the anvil 1030 and the staple cartridge 1105.

Referring again to FIGS. 4-6, the layer 1120 is releasably retained to the cartridge body 1110. The layer 1120 comprises a proximal end positioned over the proximal end 1111 (FIGS. 8-10) of the cartridge body 1110 and a distal end 1122 positioned over the distal end 1112. The staple cartridge 1105 further comprises a layer retainer 1170 which is movable between a first position in which the layer retainer 1170 releasably holds the distal end 1122 of the layer 1120 to the distal end 1112 of the cartridge body 1110 (FIGS. 4 and 5) and a second position in which the distal end 1122 of the layer 1120 is released from the distal end 1112 (FIG. 6). The layer retainer 1170 is aligned with the longitudinal slot 1114 defined in the cartridge body 1110. The layer retainer 1170 comprises a clip 1173 which is received within a clip slot 1123 defined in the cartridge body 1110 when the layer retainer 1170 is in its first position (FIG. 5). In various instances, the clip 1173 and the clip slot 1123 can be sized and configured such that the distal end 1122 of the layer 1120 is wedged therebetween and, as a result, the layer 1120 is releasably held to the distal end 1112 of the cartridge body 1110. When the layer retainer 1170 is moved into its second position (FIG. 6), the clip 1173 is removed, or at least substantially removed, from the clip slot 1123 and, as a result, the layer 1120, or at least the distal end 1122 of the layer 1120, may no longer be connected to the cartridge body 1110, as discussed in greater detail further below.

The layer retainer 1170 is movable from its first position—in which it is engaged with the layer 1120—to its second position—in which it is disengaged from the layer 1120—by the sled 1060. The sled 1060 comprises a central portion 1064 which translates within the longitudinal slot 1114 and includes a cam surface configured to engage the layer retainer 1170 and lift the layer retainer 1170 from its first position toward its second position. The layer retainer 1170 includes a switch arm 1171 extending proximally which is contacted by the central portion 1064 and pushed upwardly. The cartridge body 1110 comprises a guide slot 1172 defined therein which is configured to closely receive the layer retainer 1170 and guide the layer retainer 1170 along a longitudinal path such that, when the switch arm 1171 is pushed upwardly by the sled 1060, the clip 1173 of the layer retainer 1170 is pushed upwardly as well. In various alternative embodiments, the layer retainer 1170 can be pushed upwardly by the ramp surfaces 1063 defined on the sled 1060.

As discussed above, the layer retainer 1170 is movable between a first position in which it holds the layer 1120 to the cartridge body 1110 and a second position in which the layer 1120 is released from the cartridge body 1110. When the layer retainer 1170 is in its first position, a clip lip 1174 of the clip 1173 extends into the clip slot 1123 defined in the cartridge body 1110. In such a position, the layer 1120 is trapped between the clip lip 1174 and a clip slot lip 1124. In such a position, the clip 1173 may extend above, be recessed below, or be flush with the deck 1113 of the cartridge body 1110. When the layer retainer 1170 is moved into its second position, the clip lip 1174 is lifted relative to and/or above the deck 1113 and away from the clip slot lip 1124. In such a position, the layer 1120 can readily slide out between the clip lip 1174 and the clip slot lip 1124. In various instances, the distal end 1121 of the layer 1120 may comprise a continuous material without apertures defined therein, for example. Such an arrangement may reduce potential irritation to the tissue.

As discussed above, the layer retainer 1170 holds the layer 1120 to the cartridge body 1110 before the sled 1060 and the firing bar 1061 are advanced distally during a firing stroke. This arrangement can be helpful to hold the layer 1120 in position while the staple cartridge 1105 is positioned relative to the tissue that is to be stapled. Once the staple cartridge 1105 has been suitably positioned relative to the tissue, the anvil 1030 can be moved into a closed position to clamp the tissue against the layer 1120. At such point, the sled 1060 and the firing bar 1061 can be advanced distally through their firing stroke. The layer retainer 1170 can hold the layer 1120 to the cartridge body 1110 during the entirety of the firing stroke or, alternatively, during a portion of the firing stroke. In various instances, the layer retainer 1170 may not be release the layer 1120 from the cartridge body 1110 until or after all of the staples 1040 have been fully fired. In some instances, the layer retainer 1170 can release the layer 1120 prior to, or immediately prior to, the completion of the firing stroke In any event, the layer retainer 1170 can prevent or inhibit the layer 1120 from being pushed distally by the knife edge 1062 when the knife edge 1062 is moved distally to transect the layer 1120. In the event that the sled 1060 and the firing bar 1061 are not advanced through their full firing stroke, the layer retainer 1170 may not be defeated by the sled 1060 and, as such, the layer retainer 1170 may continue to hold the layer 1120 to the cartridge body 1110. The clip 1173 of the layer retainer 1170 and the clip slot 1123 of the layer 1120 can be sized and configured to provide a certain amount of retention force therebetween which can resist the movement of the layer 1120 prior to and during the firing stroke but permit the layer 1120 to be pulled away from the cartridge body 1110 in the event that the firing stroke is not completed.

As discussed above, a staple cartridge can include a layer retainer positioned at the distal end thereof to releasably hold the layer to the staple cartridge. In addition to or in lieu of the distal layer retainer, a staple cartridge can include a layer retainer positioned at the proximal end thereof. Turning now to FIGS. 7-10, an end effector assembly 1200 comprises a first jaw 1001 and a second jaw 1002. The first jaw 1001 comprises a staple cartridge 1205. The staple cartridge 1205 is readily removable from the first jaw 1001 and can be replaced with another staple cartridge. Other embodiments are envisioned in which the staple cartridge 1205 is not readily removable from the first jaw 1001. The staple cartridge 1205 comprises a cartridge body 1110 and an implantable layer 1220. As discussed in greater detail further below, the layer 1220 is releasably retained to the deck 1113 of the cartridge body 1110.

The second jaw 1002 is rotatable relative to the first jaw 1001 and, thus, the anvil 1030 is rotatable relative to the staple cartridge 1205; however, certain embodiments are envisioned in which the staple cartridge 1205 is rotatable relative to the anvil 1030. The sled 1060 and/or the firing bar 1061 can include a first cam 1067 (FIG. 8) configured to engage the first jaw 1001 and a second cam 1069 (FIG. 8) configured to engage the second jaw 1002 as the sled 1060 and the firing bar 1061 are advanced distally. The first cam 1067 and the second cam 1069 can co-operate to position the anvil 1030 relative to the staple cartridge 1205 and define a tissue gap therebetween. The sled 1060 and/or the firing bar 1061 can comprise a cutting surface, such as a knife edge 1062 (FIG. 8), for example, configured to incise the tissue and the layer 1220 captured between the anvil 1030 and the staple cartridge 1205.

Referring again to FIGS. 7-10, the layer 1220 is releasably retained to the cartridge body 1110. The layer 1220 comprises a proximal end 1221 positioned over the proximal end 1111 of the cartridge body 1110 and a distal end 1222 positioned over the distal end 1112. The proximal end 1221 of the layer 1220 comprises a layer retainer 1225 which is releasably held to the staple cartridge 1205. The layer retainer 1225 comprises a tail which is wedged or captured between the sled 1060 and the cartridge body 1110 when the cartridge body 1060 is in its proximal, unfired position, as illustrated in FIGS. 7-9. Referring primarily to FIG. 9, the tail of the layer retainer 1225 is positioned intermediate the central portion 1064 of the sled 1060 and a first longitudinal sidewall 1114 a of the slot 1114 and, owing to an interference fit therebetween, the proximal end 1221 of the layer 1220 is releasably held to the proximal end 1111 of the cartridge body 1110. The first sidewall 1114 a comprises a first recess 1226 defined therein configured to receive an enlarged tab 1227 defined at the end of the layer retainer tail 1225. The enlarged tab 1227 can be sized and configured such that it is prevented, or at least inhibited, from being pulled of the first recess 1226 prior to the sled 1060 being advanced distally. In addition to or in lieu of the above, the sled 1060 can include a dimple extending therefrom configured to pin the layer retainer 1225 against the first sidewall 1114 a of the longitudinal slot 1114. Also, in addition to or in lieu of the above, the first sidewall 1114 a of the longitudinal slot 1114 can include a dimple extending therefrom configured to pin the layer retainer 1225 against the sled 1060. In any event, referring primarily to FIGS. 7 and 9, the central portion 1064 of the sled 1060 includes a recess 1065 defined therein through which the layer retainer 1225 can extend when the sled 1060 is in its proximal, unfired position.

When the sled 1060 is advanced distally from its proximal position, referring primarily to FIG. 10, the layer retainer 1225 is no longer trapped intermediate the sled 1060 and the first sidewall 1114 a and, as a result, the enlarged tab 1227 can readily slide out of the first recess 1226 and the longitudinal slot 1114. In the embodiments where the proximal layer retainer 1225 is the only layer retainer holding the layer 1220 to the cartridge body, the release of the proximal layer retainer 1225 can release the layer 1220 from the cartridge body 1110. In such instances, the initiation of the firing stroke of the sled 1060 and the firing bar 1061 can release the layer 1220 from the cartridge body 1110. In the embodiments comprising a distal layer retainer in addition to the proximal layer retainer, the distal end 1222 of the layer 1220 is still releasably retained to the cartridge body 1110 eventhough the proximal end 1221 of the layer 1220 has been released.

As discussed above, an end effector assembly can include an implantable layer releasably attached to a staple cartridge. In addition to or in lieu of a staple cartridge layer, an end effector assembly can include an implantable layer releasably attached to an anvil of the end effector assembly. Referring again to FIGS. 7-10, the end effector assembly 1200 comprises an anvil layer 1320 releasably attached thereto. The anvil layer 1320 comprises a proximal end 1321 positioned adjacent a proximal end of the anvil 1030 and a distal end 1322 positioned adjacent a distal end of the anvil 1030. The proximal end 1321 of the layer 1320 comprises a layer retainer 1325 which is releasably held to the staple cartridge 1205. The layer retainer 1325 comprises a tail which is wedged or captured between the sled 1060 and the cartridge body 1110 when the cartridge body 1060 is in its proximal, unfired position, as illustrated in FIGS. 7-9. Referring primarily to FIG. 9, the tail of the layer retainer 1325 is positioned intermediate the central portion 1064 of the sled 1060 and a second longitudinal sidewall 1114 b of the slot 1114 and, owing to an interference fit therebetween, the proximal end 1321 of the layer 1320 is releasably held to the proximal end 1111 of the cartridge body 1110. The second sidewall 1114 b comprises a second recess 1326 defined therein configured to receive an enlarged tab 1327 defined at the end of the layer retainer tail 1325. The enlarged tab 1327 can be sized and configured such that it is prevented, or at least inhibited, from being pulled of the second recess 1326 prior to the sled 1060 being advanced distally. In addition to or in lieu of the above, the sled 1060 can include a dimple extending therefrom configured to pin the layer retainer 1325 against the second sidewall 1114 b of the longitudinal slot 1114. Also, in addition to or in lieu of the above, the second sidewall 1114 b of the longitudinal slot 1114 can include a dimple extending therefrom configured to pin the layer retainer 1325 against the sled 1060. In any event, referring primarily to FIGS. 7 and 9, the central portion 1064 of the sled 1060 includes a recess 1065 defined therein through which the layer retainer 1325 can extend when the sled 1060 is in its proximal, unfired position.

When the sled 1060 is advanced distally from its proximal position, referring primarily to FIG. 10, the layer retainer 1325 is no longer trapped intermediate the sled 1060 and the second sidewall 1114 b and, as a result, the enlarged tab 1327 can readily slide out of the second recess 1326 and the longitudinal slot 1114. In the embodiments where the proximal layer retainer 1375 is the only layer retainer holding the layer 1320 to the end effector 1200, the release of the proximal layer retainer 1325 can release the layer 1320 from the end effector 1200. In such instances, the initiation of the firing stroke of the sled 1060 and the firing bar 1061 can release the layer 1320 from the end effector 1200. In the embodiments comprising a distal layer retainer in addition to the proximal layer retainer, the distal end 1322 of the layer 1320 is still releasably retained to the end effector 1200 eventhough the proximal end 1321 of the layer 1320 has been released. For instance, the distal end 1322 of the layer 1320 comprises a distal layer retainer 1324 which releasably holds the distal end 1322 to the distal end of the anvil 1030.

The distal layer retainer 1324 comprises a hook which extends into the second cam slot 1009 of the anvil 1030. The layer retainer 1324 holds the layer 1320 to the anvil 1030 before the sled 1060 and the firing bar 1061 are advanced distally during a firing stroke. This arrangement can be helpful to hold the layer 1320 in position while the anvil 1030 is positioned relative to the tissue that is to be stapled. Once the anvil 1030 has been suitably positioned relative to the tissue, the anvil 1030 can be moved into a closed position to clamp the tissue against the staple cartridge 1205, for example. At such point, the layer retainer 1324 can hold the layer 1320 to the anvil 1030 during the entirety of the firing stroke or, alternatively, during a portion of the firing stroke. In either event, the anvil 1030 can be slid proximally away from the distal end 1322 of the at least partially implanted layer 1320 such that the distal layer retainer 1324 disengages from the second cam slot 1009 of the anvil 1030.

In addition to or in lieu of releasably retaining a layer to a cartridge body by way of a proximal layer retainer and/or a distal layer retainer, a layer can include one or more layer retainers releasably engaged with a longitudinal slot defined in the cartridge body, for example. Referring primarily to FIG. 8, the cartridge layer 1220 comprises a longitudinal series, or array, of tabs 1223 aligned with and releasably wedged within the longitudinal slot 1114. The series of tabs 1223 extends between the proximal end 1221 and the distal end 1222 of the layer 1220, although other configurations are contemplated which do not extend along the entire length of the layer 1220. Each tab 1223 comprises a cantilever member, for example, which extends from a body portion of the layer 1220. The tabs 1223 can be integrally-formed with the body portion of the layer 1220 and/or assembled to the body portion. In various instances, each tab 1223 can comprise at least one of a T-shaped configuration, an I-shaped configuration, and a V-shaped configuration, for example. In certain instances, the tabs 1223 can be formed by way of a laser-cutting process, for example. The tabs 1223 are engaged with the sidewalls 1114 a and 1114 b of the longitudinal slot 1114 and are configured to prevent, or at least inhibit, relative movement between the layer 1220 and the cartridge body 1110 prior to and/or during the firing stroke. During the firing stroke, the knife 1062, for example, can transect the tabs 1223 as the firing bar 1061 is advanced distally. When a tab 1223 is transected, the transected tab 1223 may no longer be able to retain the layer 1220 to the cartridge body 1110. As a result, the firing bar 1061 may progressively release the tabs 1223 from the longitudinal slot 1114. In certain embodiments, the sled 1060 and/or the firing bar 1061 can push the tabs 1223 out of the longitudinal slot 1114 as they are advanced distally. In either event, all of the tabs 1223 can be released during a completed firing stroke while only a portion of the tabs 1223 may be released during a partial firing stroke. In the event that one or more tabs 1223 remain engaged with the cartridge body 1110 after the firing stroke has been completed, the tabs 1223 can be configured to slide out of the slot 1114 when a sufficient force is applied thereto.

In addition to or in lieu of releasably retaining a layer to an anvil by way of a proximal layer retainer and/or a distal layer retainer, a layer can include one or more layer retainers releasably engaged with a longitudinal slot defined in the anvil, for example. Referring primarily to FIGS. 7 and 8, the anvil layer 1320 comprises a longitudinal series, or array, of dimples 1323 aligned with and releasably wedged within the longitudinal cam slot 1009. The series of dimples 1323 extends between the proximal end 1321 and the distal end 1322 of the layer 1320, although other configurations are contemplated which do not extend along the entire length of the layer 1320. Each dimple 1323 comprises an elevated protrusion, for example, which extends from a body portion of the layer 1320. The dimples 1323 can be integrally-formed with the body portion of the layer 1320 and/or assembled to the body portion. In various instances, each dimple 1323 can comprise a cylindrical configuration, for example. In certain instances, the dimples 1323 can be formed by way of a thermoforming and/or stretching process, for example. The dimples 1323 are engaged with the sidewalls of the cam slot 1009 and are configured to prevent, or at least inhibit, relative movement between the layer 1320 and the anvil 1030 prior to and during the firing stroke. During the firing stroke, the knife 1062, for example, can transect the dimples 1323 as the firing bar 1061 is advanced distally. When a dimple 1323 is transected, the transected dimple 1323 may no longer be able to retain the layer 1320 to the anvil 1030. As a result, the firing bar 1061 may progressively release the dimples 1323 from the longitudinal slot 1009. In certain embodiments, the cam 1069 of the firing bar 1061 can push the dimples 1323 out of the cam slot 1009 as the firing bar 1061 is advanced distally. In either event, all of the dimples 1323 can be released during a completed firing stroke while only a portion of the dimples 1323 may be released during a partial firing stroke. In the event that one or more dimples 1323 remain engaged with the anvil 1030 after the firing stroke has been completed, the dimples 1323 can be configured to slide out of the slot 1009 when a sufficient force is applied thereto.

In various instances, all of the dimples 1323 can have the same configuration. In other instances, certain dimples 1323 can have different configurations. For instance, the proximal-most dimple 1323 p can be larger than the dimples 1323 positioned distally with respect to the dimple 1323 p and, as a result, the dimple 1323 p can provide a greater retention force to the anvil 1030 than the distal dimples 1323. Such an arrangement can allow the dimple 1323 with the greatest retention force to be released at the beginning of the firing stroke. In addition to or in lieu of the above, the distal-most dimple 1323 d can be larger than dimples 1323 positioned proximally with respect to the dimple 1323 d and, as a result, the dimple 1323 d can provide a greater retention force to the anvil 1030 than the proximal dimples 1323. Such an arrangement can allow the dimple 1323 with the greatest retention force to be released at the end of the firing stroke. Moreover, such an arrangement can be more effective at inhibiting the movement of the distal end 1322 of the layer 1320 which may experience larger shear forces when the end effector 1200 is positioned relative to the tissue. Various embodiments may include dimple 1323 p and dimple 1323 d. A larger dimple 1323 can be taller, wider, and/or thicker than the other dimples 1323, for example.

In various instances, the anvil layer 1320 can comprise a body portion comprising a body thickness. The body thickness can be the thickness of the layer 1320 as measured from one side of the layer 1320, such as a side facing the anvil 1030, for example, and the other side of the layer 1320, such as a side facing away from the anvil 1030, for example. The thickness of each dimple 1323 can be measured in a similar manner, for instance. In various embodiments, the dimple thickness can be the same as the body thickness. In certain embodiments, the dimple thickness can be thinner than the body thickness. Such an arrangement can result from a thermo-forming process, for example. Moreover, such an arrangement can permit the thinner dimples 1323 to be more easily transected than the body portion. In certain instances, further to the above, all of the dimples 1323 can have the same thickness while, in other instances, certain dimples 1323 can be thicker than others, such as the proximal-most dimple 1323 and/or the distal-most dimple 1323, for example.

In various alternative embodiments, the cartridge layer 1200 can comprise dimples 1323, for example. Also, in various alternative embodiments, the anvil layer 1300 can comprise tabs 1223, for example.

In various instances, a layer of material can comprise buttress material and/or a tissue thickness compensator, for example. The layer of material can be comprised of Gore SeamGuard material, Synovis Peri-Strips material, and/or polyurethane, for example. The entire disclosure of U.S. patent application Ser. No. 13/763,095, entitled LAYER ARRANGEMENTS FOR SURGICAL STAPLE CARTRIDGES, filed on Feb. 28, 2013, now U.S. Patent Application Publication No. 2013/0161374, is incorporated by reference herein. The entire disclosures of U.S. patent application Ser. No. 13/531,619, entitled TISSUE STAPLER HAVING A THICKNESS COMPENSATOR COMPRISING INCORPORATING A HEMOSTATIC AGENT, filed on Jun. 25, 2012, now U.S. Patent Application Publication No. 2012/0318842, U.S. patent application Ser. No. 13/531,623, entitled TISSUE STAPLER HAVING A THICKNESS COMPENSATOR INCORPORATING AN OXYGEN GENERATING AGENT, filed on Jun. 25, 2012, now U.S. Patent Application Publication No. 2012/0318843, U.S. patent application Ser. No. 13/531,627, entitled TISSUE STAPLER HAVING A THICKNESS COMPENSATOR INCORPORATING AN ANTI-MICROBIAL AGENT, filed on Jun. 25, 2012, now U.S. Patent Application Publication No. 2012/0312860, and U.S. patent application Ser. No. 13/531,630, entitled TISSUE STAPLER HAVING A THICKNESS COMPENSATOR INCORPORATING AN ANTI-INFLAMMATORY AGENT, filed on Jun. 25, 2012, now U.S. Patent Application Publication No. 2012/0318844, are incorporated by reference herein. A layer can be comprised of a bioabsorbable material and/or a non-bioabsorbable material. In some instances, a layer of material can be attached to the deck. In at least one instance, at least one adhesive can be utilized to releasably adhere the layer to the deck. In some instances, the layer of material can be releasably attached to the deck utilizing one or more sutures or straps, for example. In certain instances, the layer can comprise a solid piece of material. In some instances, the layer can include apertures defined therein.

Further to the above, the staples being deployed from a staple cartridge can puncture the layer before entering into the tissue. The staples may also re-puncture the layer as they are being deformed by the anvil. In various instances, thicker or more puncture-resistant strips of polymer could be integrated into the layer, for example. For instance, such strips could be integrated into the tissue-contacting surface of the layer. In at least one instance, each strip could be 0.003″ thick and comprised of 90/10 PLA/PCL, for example. In certain instances, each strip could be 0.006″ thick 25/75 PGA/PCL, for example. The strips could be welded into the foam as part of a felting process, for example. The disclosure of U.S. patent application Ser. No. 14/187,383, entitled IMPLANTABLE LAYERS AND METHODS FOR ALTERING IMPLANTABLE LAYERS FOR USE WITH SURGICAL FASTENING INSTRUMENTS is incorporated by reference in its entirety. The felting process could serve another purpose which is to create a closed cell foam and/or a continuous tissue contacting surface. In some instances, separate thin film strips could be welded into the tissue-contacting side of the foam. The various methods disclosed herein can create a composite absorbable material with features or zones aligned with the staples that have differing properties for initial staple puncturing, forming, and re-piercing.

A layer, such as buttress material, for example, may be made from any biocompatible material. Buttress material may be formed from a natural material and/or a synthetic material. Buttress material may be bioabsorbable and/or non-bioabsorbable. It should be understood that any combination of natural, synthetic, bioabsorbable and non-bioabsorbable materials may be used to form buttress material. Some non-limiting examples of materials from which the buttress material may be made include, but are not limited to, poly(lactic acid), poly (glycolic acid), poly (hydroxybutyrate), poly (phosphazine), polyesters, polyethylene glycols, polyethylene oxides, polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinyl alcohols, polyacrylic acid, polyacetate, polycaprolactone, polypropylene, aliphatic polyesters, glycerols, poly(amino acids), copoly (ether-esters), polyalkylene oxalates, polyamides, poly (iminocarbonates), polyalkylene oxalates, polyoxaesters, polyorthoesters, polyphosphazenes and copolymers, block copolymers, homopolymers, blends and/or combinations thereof, for example.

Natural biological polymers can be used in forming the buttress material. Suitable natural biological polymers include, but are not limited to, collagen, gelatin, fibrin, fibrinogen, elastin, keratin, albumin, hydroxyethyl cellulose, cellulose, oxidized cellulose, hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, chitan, chitosan, and/or combinations thereof, for example. Natural biological polymers may be combined with any of the other polymeric materials described herein to produce the buttress material. Collagen of human and/or animal origin, e.g., type I porcine or bovine collagen, type I human collagen or type III human collagen may be used to form the buttress material. The buttress material may be made from denatured collagen or collagen which has at least partially lost its helical structure through heating or any other method, consisting mainly of non-hydrated a chains, of molecular weight close to 100 kDa, for example. The term “denatured collagen” means collagen which has lost its helical structure. The collagen used for the porous layer as described herein may be native collagen or atellocollagen, notably as obtained through pepsin digestion and/or after moderate heating as defined previously, for example. The collagen may have been previously chemically modified by oxidation, methylation, succinylation, ethylation and/or any other known process.

Where the buttress material is fibrous, the fibers may be filaments or threads suitable for knitting or weaving or may be staple fibers, such as those frequently used for preparing non-woven materials. The fibers may be made from any biocompatible material. The fibers may be formed from a natural material or a synthetic material. The material from which the fibers are formed may be bioabsorbable or non-bioabsorbable. It should be understood that any combination of natural, synthetic, bioabsorbable and non-bioabsorbable materials may be used to form the fibers. Some non-limiting examples of materials from which the fibers may be made include, but are not limited to, poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine), polyesters, polyethylene glycols, polyethylene oxides, polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinyl alcohols, polyacrylic acid, polyacetate, polycaprolactone, polypropylene, aliphatic polyesters, glycerols, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyamides, poly (iminocarbonates), polyalkylene oxalates, polyoxaesters, polyorthoesters, polyphosphazenes and copolymers, block copolymers, homopolymers, blends and/or combinations thereof. Where the buttress material is fibrous, the buttress material may be formed using any method suitable to forming fibrous structures including, but not limited to, knitting, weaving, non-woven techniques and the like, for example. Where the buttress material is a foam, the porous layer may be formed using any method suitable to forming a foam or sponge including, but not limited to the lyophilization or freeze-drying of a composition, for example.

The buttress material may possesses haemostatic properties. Illustrative examples of materials which may be used in providing the buttress material with the capacity to assist in stopping bleeding or hemorrhage include, but are not limited to, poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(caprolactone), poly(dioxanone), polyalkyleneoxides, copoly(ether-esters), collagen, gelatin, thrombin, fibrin, fibrinogen, fibronectin, elastin, albumin, hemoglobin, ovalbumin, polysaccharides, hyaluronic acid, chondroitin sulfate, hydroxyethyl starch, hydroxyethyl cellulose, cellulose, oxidized cellulose, hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, chitan, chitosan, agarose, maltose, maltodextrin, alginate, clotting factors, methacrylate, polyurethanes, cyanoacrylates, platelet agonists, vasoconstrictors, alum, calcium, RGD peptides, proteins, protamine sulfate, epsilon amino caproic acid, ferric sulfate, ferric subsulfates, ferric chloride, zinc, zinc chloride, aluminum chloride, aluminum sulfates, aluminum acetates, permanganates, tannins, bone wax, polyethylene glycols, fucans and/or combinations thereof, for example. The use of natural biological polymers, and in particular proteins, may be useful in forming buttress material having haemostatic properties. Suitable natural biological polymers include, but are not limited to, collagen, gelatin, fibrin, fibrinogen, elastin, keratin, albumin and/or combinations thereof, for example. Natural biological polymers may be combined with any other haemostatic agent to produce the porous layer of the buttress. The entire disclosure of U.S. Pat. No. 8,496,683, entitled BUTTRESS AND SURGICAL STAPLING APPARATUS, which issued on Jul. 30, 2013, is incorporated by reference herein.

In various circumstances, the tissue thickness compensator assembly may comprise a polymeric composition. The polymeric composition may comprise one or more synthetic polymer and/or one or more non-synthetic polymer. The synthetic polymer may comprise a synthetic absorbable polymer and/or a synthetic non-absorbable polymer. In various circumstances, the polymeric composition may comprise a biocompatible foam, for example. The biocompatible foam may comprise a porous, open cell foam and/or a porous, closed cell foam, for example. The biocompatible foam can have a uniform pore morphology or may have a gradient pore morphology (i.e. small pores gradually increasing in size to large pores across the thickness of the foam in one direction). In various circumstances, the polymeric composition may comprise one or more of a porous scaffold, a porous matrix, a gel matrix, a hydrogel matrix, a solution matrix, a filamentous matrix, a tubular matrix, a composite matrix, a membranous matrix, a biostable polymer, and a biodegradable polymer, and combinations thereof. For example, the tissue thickness compensator assembly may comprise a foam reinforced by a filamentous matrix or may comprise a foam having an additional hydrogel layer that expands in the presence of bodily fluids to further provide the compression on the tissue. In various circumstances, a tissue thickness compensator assembly could also be comprised of a coating on a material and/or a second or third layer that expands in the presence of bodily fluids to further provide the compression on the tissue. Such a layer could be a hydrogel that could be a synthetic and/or naturally derived material and could be either biodurable and/or biodegradable, for example. In certain circumstances, a tissue thickness compensator assembly could be reinforced with fibrous non-woven materials or fibrous mesh type elements, for example, that can provide additional flexibility, stiffness, and/or strength. In various circumstances, a tissue thickness compensator assembly that has a porous morphology which exhibits a gradient structure such as, for example, small pores on one surface and larger pores on the other surface. Such morphology could be more optimal for tissue in-growth or hemostatic behavior. Further, the gradient could be also compositional with a varying bio-absorption profile. A short term absorption profile may be preferred to address hemostasis while a long term absorption profile may address better tissue healing without leakages.

Examples of non-synthetic polymers include, but are not limited to, lyophilized polysaccharide, glycoprotein, elastin, proteoglycan, gelatin, collagen, and oxidized regenerated cellulose (ORC). Examples of synthetic absorbable polymers include, but are not limited to, poly(lactic acid) (PLA), poly(L-lactic acid) (PLLA), polycaprolactone (PCL), polyglycolic acid (PGA), poly(trimethylene carbonate) (TMC), polyethylene terephthalate (PET), polyhydroxyalkanoate (PHA), a copolymer of glycolide and ε-caprolactone (PGCL), a copolymer of glycolide and-trimethylene carbonate, poly(glycerol sebacate) (PGS), polydioxanone, poly(orthoesters), polyanhydrides, polysaccharides, poly(ester-amides), tyrosine-based polyarylates, tyrosine-based polyiminocarbonates, tyrosine-based polycarbonates, poly(D,L-lactide-urethane), poly(B-hydroxybutyrate), poly(E-caprolactone), polyethyleneglycol (PEG), poly[bis(carboxylatophenoxy) phosphazene], poly(amino acids), pseudo-poly(amino acids), absorbable polyurethanes, and combinations thereof. In various circumstances, the polymeric composition may comprise from approximately 50% to approximately 90% by weight of the polymeric composition of PLLA and approximately 50% to approximately 10% by weight of the polymeric composition of PCL, for example. In at least one embodiment, the polymeric composition may comprise approximately 70% by weight of PLLA and approximately 30% by weight of PCL, for example. In various circumstances, the polymeric composition may comprise from approximately 55% to approximately 85% by weight of the polymeric composition of PGA and 15% to 45% by weight of the polymeric composition of PCL, for example. In at least one embodiment, the polymeric composition may comprise approximately 65% by weight of PGA and approximately 35% by weight of PCL, for example. In various circumstances, the polymeric composition may comprise from approximately 90% to approximately 95% by weight of the polymeric composition of PGA and approximately 5% to approximately 10% by weight of the polymeric composition of PLA, for example.

In various circumstances, the synthetic absorbable polymer may comprise a bioabsorbable, biocompatible elastomeric copolymer. Suitable bioabsorbable, biocompatible elastomeric copolymers include but are not limited to copolymers of epsilon-caprolactone and glycolide (preferably having a mole ratio of epsilon-caprolactone to glycolide of from about 30:70 to about 70:30, preferably 35:65 to about 65:35, and more preferably 45:55 to 35:65); elastomeric copolymers of epsilon-caprolactone and lactide, including L-lactide, D-lactide blends thereof or lactic acid copolymers (preferably having a mole ratio of epsilon-caprolactone to lactide of from about 35:65 to about 65:35 and more preferably 45:55 to 30:70) elastomeric copolymers of p-dioxanone (1,4-dioxan-2-one) and lactide including L-lactide, D-lactide and lactic acid (preferably having a mole ratio of p-dioxanone to lactide of from about 40:60 to about 60:40); elastomeric copolymers of epsilon-caprolactone and p-dioxanone (preferably having a mole ratio of epsilon-caprolactone to p-dioxanone of from about 30:70 to about 70:30); elastomeric copolymers of p-dioxanone and trimethylene carbonate (preferably having a mole ratio of p-dioxanone to trimethylene carbonate of from about 30:70 to about 70:30); elastomeric copolymers of trimethylene carbonate and glycolide (preferably having a mole ratio of trimethylene carbonate to glycolide of from about 30:70 to about 70:30); elastomeric copolymer of trimethylene carbonate and lactide including L-lactide, D-lactide, blends thereof or lactic acid copolymers (preferably having a mole ratio of trimethylene carbonate to lactide of from about 30:70 to about 70:30) and blends thereof. In one embodiment, the elastomeric copolymer is a copolymer of glycolide and epsilon-caprolactone. In another embodiment, the elastomeric copolymer is a copolymer of lactide and epsilon-caprolactone.

The disclosures of U.S. Pat. No. 5,468,253, entitled ELASTOMERIC MEDICAL DEVICE, which issued on Nov. 21, 1995, and U.S. Pat. No. 6,325,810, entitled FOAM BUTTRESS FOR STAPLING APPARATUS, which issued on Dec. 4, 2001, are hereby incorporated by reference in their respective entireties.

In various circumstances, the synthetic absorbable polymer may comprise one or more of 90/10 poly(glycolide-L-lactide) copolymer, commercially available from Ethicon, Inc. under the trade designation VICRYL (polyglactic 910), polyglycolide, commercially available from American Cyanamid Co. under the trade designation DEXON, polydioxanone, commercially available from Ethicon, Inc. under the trade designation PDS, poly(glycolide-trimethylene carbonate) random block copolymer, commercially available from American Cyanamid Co. under the trade designation MAXON, 75/25 poly(glycolide-E-caprolactone-poliglecaprolactone 25) copolymer, commercially available from Ethicon under the trade designation MONOCRYL, for example.

Examples of synthetic non-absorbable polymers include, but are not limited to, foamed polyurethane, polypropylene (PP), polyethylene (PE), polycarbonate, polyamides, such as nylon, polyvinylchloride (PVC), polymethylmetacrylate (PMMA), polystyrene (PS), polyester, polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polytrifluorochloroethylene (PTFCE), polyvinylfluoride (PVF), fluorinated ethylene propylene (FEP), polyacetal, polysulfone, and combinations thereof. The synthetic non-absorbable polymers may include, but are not limited to, foamed elastomers and porous elastomers, such as, for example, silicone, polyisoprene, and rubber. In various circumstances, the synthetic polymers may comprise expanded polytetrafluoroethylene (ePTFE), commercially available from W. L. Gore & Associates, Inc. under the trade designation GORE-TEX Soft Tissue Patch and co-polyetherester urethane foam commercially available from Polyganics under the trade designation NASOPORE.

The polymeric composition of a tissue thickness compensator assembly may be characterized by percent porosity, pore size, and/or hardness, for example. In various circumstances, the polymeric composition may have a percent porosity from approximately 30% by volume to approximately 99% by volume, for example. In certain circumstances, the polymeric composition may have a percent porosity from approximately 60% by volume to approximately 98% by volume, for example. In various circumstances, the polymeric composition may have a percent porosity from approximately 85% by volume to approximately 97% by volume, for example. In at least one embodiment, the polymeric composition may comprise approximately 70% by weight of PLLA and approximately 30% by weight of PCL, for example, and can comprise approximately 90% porosity by volume, for example. In at least one such embodiment, as a result, the polymeric composition would comprise approximately 10% copolymer by volume. In at least one embodiment, the polymeric composition may comprise approximately 65% by weight of PGA and approximately 35% by weight of PCL, for example, and can have a percent porosity from approximately 93% by volume to approximately 95% by volume, for example. In various circumstances, the polymeric composition may comprise a greater than 85% porosity by volume. The polymeric composition may have a pore size from approximately 5 micrometers to approximately 2000 micrometers, for example. In various circumstances, the polymeric composition may have a pore size between approximately 10 micrometers to approximately 100 micrometers, for example. In at least one such embodiment, the polymeric composition can comprise a copolymer of PGA and PCL, for example. In certain circumstances, the polymeric composition may have a pore size between approximately 100 micrometers to approximately 1000 micrometers, for example. In at least one such embodiment, the polymeric composition can comprise a copolymer of PLLA and PCL, for example. According to certain aspects, the hardness of a polymeric composition may be expressed in terms of the Shore Hardness, which can defined as the resistance to permanent indentation of a material as determined with a durometer, such as a Shore Durometer. In order to assess the durometer value for a given material, a pressure is applied to the material with a durometer indenter foot in accordance with ASTM procedure D2240-00, entitled, “Standard Test Method for Rubber Property-Durometer Hardness”, the entirety of which is incorporated herein by reference. The durometer indenter foot may be applied to the material for a sufficient period of time, such as 15 seconds, for example, wherein a reading is then taken from the appropriate scale. Depending on the type of scale being used, a reading of 0 can be obtained when the indenter foot completely penetrates the material, and a reading of 100 can be obtained when no penetration into the material occurs. This reading is dimensionless. In various circumstances, the durometer may be determined in accordance with any suitable scale, such as Type A and/or Type OO scales, for example, in accordance with ASTM D2240-00. In various circumstances, the polymeric composition of a tissue thickness compensator assembly may have a Shore A hardness value from approximately 4 A to approximately 16 A, for example, which is approximately 45 OO to approximately 65 OO on the Shore OO range. In at least one such embodiment, the polymeric composition can comprise a PLLA/PCL copolymer or a PGA/PCL copolymer, for example. In various circumstances, the polymeric composition of a tissue thickness compensator assembly may have a Shore A Hardness value of less than 15 A. In various circumstances, the polymeric composition of a tissue thickness compensator assembly may have a Shore A Hardness value of less than 10 A. In various circumstances, the polymeric composition of a tissue thickness compensator assembly may have a Shore A Hardness value of less than 5 A. In certain circumstances, the polymeric material may have a Shore OO composition value from approximately 35 OO to approximately 75 OO, for example.

In various circumstances, the polymeric composition may have at least two of the above-identified properties. In various circumstances, the polymeric composition may have at least three of the above-identified properties. The polymeric composition may have a porosity from 85% to 97% by volume, a pore size from 5 micrometers to 2000 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. In at least one embodiment, the polymeric composition may comprise 70% by weight of the polymeric composition of PLLA and 30% by weight of the polymeric composition of PCL having a porosity of 90% by volume, a pore size from 100 micrometers to 1000 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. In at least one embodiment, the polymeric composition may comprise 65% by weight of the polymeric composition of PGA and 35% by weight of the polymeric composition of PCL having a porosity from 93% to 95% by volume, a pore size from 10 micrometers to 100 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example.

In various circumstances, the polymeric composition may comprise a pharmaceutically active agent. The polymeric composition may release a therapeutically effective amount of the pharmaceutically active agent. In various circumstances, the pharmaceutically active agent may be released as the polymeric composition is desorbed/absorbed. In various circumstances, the pharmaceutically active agent may be released into fluid, such as, for example, blood, passing over or through the polymeric composition. Examples of pharmaceutically active agents may include, but are not limited to, hemostatic agents and drugs, such as, for example, fibrin, thrombin, and oxidized regenerated cellulose (ORC); anti-inflammatory drugs, such as, for example, diclofenac, aspirin, naproxen, sulindac, and hydrocortisone; antibiotic and antimicrobial drug or agents, such as, for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxin B, chloramphenicol; and anticancer agents, such as, for example, cisplatin, mitomycin, adriamycin.

Various methods are disclosed herein for manufacturing a tissue thickness compensator. Such methods could be used to manufacture any suitable layer for use with a fastener cartridge and/or a surgical fastening instrument, for example. Such a layer can comprise a less than one hundred percent dense composition which can be created utilizing any suitable process. For instance, such processes can include, for example, extruding, injection molding, weaving, lyophilization, gas-foaming, and/or melt-blowing processes. Some processes may produce a foam while other processes may not produce a foam; however, in any event, all such embodiments are contemplated for use with all of the embodiments disclosed herein.

The entire disclosures of:

U.S. Pat. No. 5,403,312, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, which issued on Apr. 4, 1995;

U.S. Pat. No. 7,000,818, entitled SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on Feb. 21, 2006;

U.S. Pat. No. 7,422,139, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK, which issued on Sep. 9, 2008;

U.S. Pat. No. 7,464,849, entitled ELECTRO-MECHANICAL SURGICAL INSTRUMENT WITH CLOSURE SYSTEM AND ANVIL ALIGNMENT COMPONENTS, which issued on Dec. 16, 2008;

U.S. Pat. No. 7,670,334, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, which issued on Mar. 2, 2010;

U.S. Pat. No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS, which issued on Jul. 13, 2010;

U.S. Pat. No. 8,393,514, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, which issued on Mar. 12, 2013;

U.S. patent application Ser. No. 11/343,803, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES; now U.S. Pat. No. 7,845,537;

U.S. patent application Ser. No. 12/031,573, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT HAVING RF ELECTRODES, filed Feb. 14, 2008;

U.S. patent application Ser. No. 12/031,873, entitled END EFFECTORS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT, filed Feb. 15, 2008, now U.S. Pat. No. 7,980,443;

U.S. patent application Ser. No. 12/235,782, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT, now U.S. Pat. No. 8,210,411;

U.S. patent application Ser. No. 12/249,117, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, now U.S. Pat. No. 8,608,045;

U.S. patent application Ser. No. 12/647,100, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY, filed Dec. 24, 2009; now U.S. Pat. No. 8,220,688;

U.S. patent application Ser. No. 12/893,461, entitled STAPLE CARTRIDGE, filed Sep. 29, 2012, now U.S. Pat. No. 8,733,613;

U.S. patent application Ser. No. 13/036,647, entitled SURGICAL STAPLING INSTRUMENT, filed Feb. 28, 2011, now U.S. Pat. No. 8,561,870;

U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Patent Application Publication No. 2012/0298719;

U.S. patent application Ser. No. 13/524,049, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, filed on Jun. 15, 2012; now U.S. Patent Application Publication No. 2013/0334278;

U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013; now U.S. Patent Application Publication No. 2014/0263551;

U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013; now U.S. Patent Application Publication No. 2014/0263552;

U.S. Patent Application Publication No. 2007/0175955, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM, filed Jan. 31, 2006; and

U.S. Patent Application Publication No. 2010/0264194, entitled SURGICAL STAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR, filed Apr. 22, 2010, now U.S. Pat. No. 8,308,040, are hereby incorporated by reference herein.

Although the various embodiments of the devices have been described herein in connection with certain disclosed embodiments, many modifications and variations to those embodiments may be implemented. Also, where materials are disclosed for certain components, other materials may be used. Furthermore, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The foregoing description and following claims are intended to cover all such modification and variations.

The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

Preferably, the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.

While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 

What is claimed is:
 1. A surgical stapling apparatus for stapling tissue, comprising: a cartridge body, comprising: a proximal end; a distal end; a deck comprising a tissue-supporting surface; and a plurality of staple cavities; a plurality of staples removably stored in said staple cavities; a firing member movable between a proximal position toward a distal position to eject said staples from said staple cavities; a layer positioned above said deck, wherein said staples are configured to implant said layer against the tissue when said staples are ejected from said staple cavities; and a layer retainer configured to releasably hold said layer to said deck, wherein said firing member is configured to engage said layer retainer and lift said layer retainer relative to said deck.
 2. The surgical stapling apparatus of claim 1, wherein said layer retainer comprises a clip movable between a retaining position and a released position, wherein said deck comprises a clip slot, and wherein a portion of said layer is wedged between said clip and said clip slot when said clip is in said retaining position.
 3. The surgical stapling apparatus of claim 1, wherein said layer retainer comprises a retainer lip, wherein said deck comprises a deck lip, and wherein said retainer lip and said deck lip releasably hold said layer therebetween.
 4. The surgical stapling apparatus of claim 1, wherein said layer comprises a proximal portion and a distal portion, wherein said layer retainer is positioned at said distal end of said cartridge body and is configured to releasably hold said distal portion against said deck, wherein said proximal portion is wedged between said firing member and said cartridge body when said firing member is in said proximal position, and wherein said proximal portion is released when said firing member is moved toward said distal position.
 5. The surgical stapling apparatus of claim 1, wherein said cartridge body comprises a longitudinal slot configured to receive a portion of said firing member therein, wherein said layer comprises a series of tabs aligned with and releasably wedged within said longitudinal slot, and wherein said firing member is configured to engage said tabs to progressively release said tabs from said longitudinal slot.
 6. A surgical stapling apparatus for stapling tissue, comprising: a cartridge body, comprising: a proximal end; a distal end; a deck comprising a tissue-supporting surface; and a plurality of staple cavities; a plurality of staples removably stored in said staple cavities; a plurality of staple drivers comprising a proximal driver and a distal driver; a firing member movable from a proximal position toward a distal position to lift said staple drivers toward said deck to eject said staples from said staple cavities; a layer positioned above said deck, wherein said staples are configured to implant said layer against the tissue when said staples are ejected from said staple cavities; and a layer retainer configured to releasably hold said layer to said deck, wherein said distal driver is configured to retract said layer retainer relative to said deck.
 7. The surgical stapling apparatus of claim 6, wherein said layer retainer comprises a pin movable between a retaining position and a released position, wherein said layer comprises a pin aperture, wherein said pin is positioned in said pin aperture when said layer retainer is in said retaining position, and wherein said pin is disengaged from said pin aperture when said layer retainer is in said released position.
 8. The surgical stapling apparatus of claim 6, wherein said layer comprises a proximal portion and a distal portion, wherein said layer retainer is positioned at said distal end of said cartridge body and is configured to releasably hold said distal portion relative to said deck, wherein said proximal portion is wedged between said firing member and said cartridge body when said firing member is in said proximal position, and wherein said proximal portion is released when said firing member is moved toward said distal position.
 9. The surgical stapling apparatus of claim 6, wherein said cartridge body comprises a longitudinal slot configured to receive a portion of said firing member therein, wherein said layer comprises a series of tabs aligned with and releasably wedged within said longitudinal slot, and wherein said firing member is configured to engage said tabs to progressively release said tabs from said longitudinal slot.
 10. A surgical stapling apparatus for stapling tissue, comprising: a cartridge body, comprising: a proximal end; a distal end; a deck comprising a tissue-supporting surface; a plurality of staple cavities; and a longitudinal slot; a plurality of staples removably stored in said staple cavities; a firing member movable from a proximal position toward a distal position to eject said staples from said staple cavities, wherein a portion of said firing member is positioned within said longitudinal slot; a layer positioned above said deck, wherein said staples are configured to implant said layer against the tissue when said staples are ejected from said staple cavities; and a longitudinal series of layer retainers configured to releasably hold said layer to said deck, wherein said layer retainers are aligned with and releasably wedged within said longitudinal slot, and wherein said firing member is configured to engage said layer retainers to progressively release said layer retainers from said longitudinal slot.
 11. The surgical stapling apparatus of claim 10, wherein said longitudinal slot comprises a first longitudinal sidewall and a second longitudinal sidewall, and wherein each said layer retainer comprises a tab releasably wedged between said first longitudinal sidewall and said second longitudinal sidewall.
 12. The surgical stapling apparatus of claim 10, wherein said layer comprises an implantable body, and wherein said layer retainers are integrally formed with said implantable body.
 13. The surgical stapling apparatus of claim 10, further comprising: a plurality of staple drivers configured to lift said staples toward said deck, wherein said staple drivers comprise a proximal staple driver and a distal staple driver; and a distal layer retainer configured to releasably hold said layer to said deck, wherein said distal staple driver is configured to retract said distal layer retainer relative to said deck.
 14. The surgical stapling apparatus of claim 13, wherein said distal layer retainer comprises a pin movable between a retaining position and a released position, wherein said layer comprises a pin aperture, wherein said pin is positioned in said pin aperture when said distal layer retainer is in said retaining position, and wherein said pin is disengaged from said pin aperture when said distal layer retainer is in said released position.
 15. The surgical stapling apparatus of claim 10, wherein said layer comprises a proximal portion and a distal portion, wherein said proximal portion is wedged between said firing member and said cartridge body when said firing member is in said proximal position, and wherein said proximal portion is released when said firing member is moved toward said distal position.
 16. The surgical stapling apparatus of claim 10, further comprising a distal layer retainer configured to releasably hold said layer to said deck, wherein said firing member is configured to engage said distal layer retainer and lift said distal layer retainer relative to said deck.
 17. The surgical stapling apparatus of claim 16, wherein said distal layer retainer comprises a clip movable between a retaining position and a released position, wherein said deck comprises a clip slot, and wherein a portion of said layer is wedged between said clip and said clip slot when said clip is in said retaining position.
 18. The surgical stapling apparatus of claim 16, wherein said distal layer retainer comprises a retainer lip, wherein said deck comprises a deck lip, and wherein said retainer lip and said deck lip releasably hold said layer therebetween.
 19. A surgical stapling apparatus for stapling tissue, comprising: a staple cartridge, comprising: a cartridge body, comprising: a proximal end; a distal end; a longitudinal slot comprising a first sidewall and a second sidewall; a deck comprising a tissue-supporting surface; and a plurality of staple cavities; a plurality of staples removably stored in said staple cavities; and a firing member movable from a proximal position toward a distal position to eject said staples from said staple cavities, wherein said longitudinal slot is configured to receive a portion of said firing member; an anvil configured to deform said staples; and a layer positioned against said anvil, wherein said staples are configured to implant said layer against the tissue when said staples are ejected from said staple cavities, wherein said layer comprises a layer retainer positioned intermediate said firing member and said first sidewall when said firing member is in said proximal position, and wherein said layer retainer is released when said firing member is moved toward said distal position.
 20. The surgical stapling apparatus of claim 19, wherein said anvil includes a longitudinal anvil slot configured to receive a portion of said firing member, wherein said layer further comprises a longitudinal series of anvil layer retainers configured to releasably hold said layer to said anvil, wherein said anvil layer retainers are aligned with and releasably wedged within said longitudinal anvil slot, and wherein said firing member is configured to engage said anvil layer retainers to progressively release said anvil layer retainers from said longitudinal anvil slot.
 21. The surgical stapling apparatus of claim 20, wherein said layer comprises a layer body, wherein said layer body comprises a body thickness, wherein each said anvil layer retainer comprises a dimple extending from said layer body, and wherein each said dimple comprises a dimple thickness which is thinner than said body thickness.
 22. The surgical stapling apparatus of claim 20 wherein each said anvil layer retainer comprises a dimple, wherein at least one said dimple comprises a first dimple having a first dimple thickness, and wherein at least one said dimple comprises a second dimple having a second dimple thickness which is thinner than said first dimple thickness.
 23. The surgical stapling apparatus of claim 22, wherein a distal-most dimple comprises a said first dimple, wherein a proximal-most dimple comprises a said first dimple, and wherein said second dimple is positioned intermediate said proximal-most dimple and said distal-most dimple.
 24. The surgical stapling apparatus of claim 22, wherein said firing member comprises a cutting portion, and wherein said cutting portion is configured to incise said dimples when said firing member is moved from said proximal position toward said distal position.
 25. The surgical stapling apparatus of claim 19, further comprising a cartridge layer releasably attached to said cartridge body by at least one cartridge layer retainer.
 26. The surgical stapling apparatus of claim 25, wherein said at least one cartridge layer retainer comprises a longitudinal series of cartridge layer retainers configured to releasably hold said cartridge layer to said cartridge body, wherein said cartridge layer retainers are aligned with and releasably wedged within said longitudinal slot, and wherein said firing member is configured to engage said cartridge layer retainers to progressively release said cartridge layer retainers from said longitudinal slot.
 27. The surgical stapling apparatus of claim 26, wherein said firing member comprises a first cam configured to engage said anvil and a second cam configured to engage said staple cartridge, wherein said first cam is configured to progressively release anvil layer retainers from an anvil longitudinal slot, and wherein said second cam is configured to progressively release said cartridge layer retainers from said longitudinal slot of said cartridge body.
 28. The surgical stapling apparatus of claim 27, wherein said first cam and said second cam are configured to control a tissue gap between said anvil and said staple cartridge.
 29. The surgical stapling apparatus of claim 25, wherein said at least one cartridge layer retainer comprises a layer retainer positioned at said distal end. 